Immune cells use signals to coordinate their attack on an infectious agent or to downgrade their attack after danger has past. The signals that they use are proteins called cytokines, of which there are about 25. During immunological disorders, cytokines can either signal or control a self-directed attack on the body, and therefore much attention has been paid to cytokines during autoimmune conditions. Yet there are few ways to query individual cells for cytokine expression and until now there have been no ways to do so on the small samples of immune cells isolated from skin and other inflamed tissues. [unreadable] Trellis' approach to measuring single cell cytokine expression is to capture the cytokines produced by single cells while they lie on a flat plastic surface. These cell "footprints" can then be probed by multihued nanoscale beads, each bead type linked to a different anti-cytokine antibody. This method has already revealed that the language of immune cells is not as simple as it is sometimes portrayed. The high level of diversity of immune cells in normal samples may be much diminished in disease or cell types that are rare in normal tissue may become significantly amplified. This is one question that can be explored with Trellis' CellSpot-CK technology. Other questions relate to staging disease based on direct exploration of the cellular profiles that underlie disease manifestation. Such information should be very useful in selecting treatment regimens for these chronic, progressive diseases as well as for monitoring patient responses. [unreadable] Before introducing CellSpot-CK to cellular immunologists throughout the world, Trellis will need to make the instrument used to read CellSpots more robust, easier to use, and faster. This is one Specific Aim in this Phase II proposal. The other Specific Aims relate to characterizing the cytokine language of immune cells in both health and disease. [unreadable] The successful development of CellSpot-CK will make available to researchers a new tool for understanding the role of the immune system in many chronic conditions like eczema, psoriasis, arthritis, and asthma. It will also provide a tool to learn how immune cells respond to drugs under development as cures for these diseases. Longer term, it may provide an important clinical "theranostic" assay (therapy selection based on a diagnostic procedure). [unreadable] [unreadable]